Frequent periodic testing of the air brake systems of semi-truck trailers (tractor-trailers) is required under federal regulations, and is important to vehicle safety. These tests are conducted by employees of the trucking industry on a regular basis.
The testing of an air brake system of a tractor-trailer conventionally is conducted after the tractor has been coupled to the trailer, with the air lines between the tractor and trailer connected. This coupled/connected condition is necessary because it is the tractor, not the trailer, which is equipped to generate and control compressed air. With the air lines from the tractor to the trailer connected, trailer air system is charged through the tractor air system via its brake valve equipment, and the brakes are applied and released sequentially via the tractor brake pedal.
The conventional test method is not only handicapped by the requirement of providing a coupled trailer, but also by the need to employ two people, namely one operating the trailer systems from the cab of a tractor (for instance, depressing and releasing the brake pedal) and one positioned to observe trailer brake operation. The trailer brake operation must be eyed from a position closely proximate to, or beneath, the trailer because the brakes are located about the trailer axles. Such observation is not possible from inside the cab of a coupled tractor. And the operation of a tractor""s brake pedal is generally not possible from any position except inside the tractor cab.
Similar circumscriptions attend the testing of a trailer""s electrical light system. A trailer typically has tail lights, brake lights, turn signals, and other lights, but the source of electrical power and the light controls are not in the trailer, but instead in the tractor. It is generally not possible to visually inspect these lights, particularly those at the rear of a trailer, from the cab of a coupled tractor, and generally it is not possible to control these lights from any position other than the tractor cab.
One object of the present invention is to provide a relatively simple and inexpensive apparatus for testing at least the air brakes of trailers independent of any tractor air brake system. Another object of the present invention is to provide a lightweight and portable apparatus through which at least the air brakes of a trailer can be applied and released, particularly for the purpose of testing such brakes. A further object of the present invention is to provide such apparatus which can be fully controlled by a single person positioned at the location of the brakes, in full view of the operation of the trailer brake system when the brakes are applied and released through such portable test apparatus. An additional object of the present invention is a such test apparatus which not only controls at least the application and release of the trailer brakes, but also through which the trailer brakes can be held in a charged position while the loss of air pressure in the system over a period of time is measured.
The present invention is a relatively simple and inexpensive apparatus for testing at least the air brakes of trailers, which includes a portable air-brake governing or actuation system and a hand-held control pendent, operating off an independent compressed air supply. Without the coupling of, and connections with, a tractor, the air brakes of a trailer can be applied and released, and held in a charged mode for a period of time during which any loss of air pressure can be monitored. Using the apparatus of the present invention, a single person can conduct the entire air brake test process, including applying and releasing the brakes while simultaneously visually and manually inspecting the brakes. The apparatus in at least some embodiments can be used to test trailer lights using the same portable power source as the brake test device. The invention also includes a testing system which includes the test device interposed between a source of compressed air and the air system of a trailer. The invention also includes a method using the apparatus of the present invention, whereby an air brake test process can be conducted, including applying and releasing the brakes while observing and/or inspecting the brakes.